Swab



Feb. 10, 1942. K. F. BUDD 2,272,963

SWAB

Filed Oct. 19, 1939 Patented Feb. 10, 1942 UNlTED STATES OFFICE Kline F. Budd, Houston, Tex.

Application October 19, 1939, Serial No. 300,155

7 Claims.

This invention relates to a swab.

An object of the invention is to provide a swab particularly designed for use in removing fluid, such as heavy drilling fluid, from a well preparatory to bringing in the well.

It is another object of the invention to provide a swab that will readily move to open position as it moves downwardly through the uid, or in case of strong gas pressure from beneath, but

which upon upward movement of the swab will close to trap the liquid in the well pipe above it so that the trapped liquid may be discharged from the well as the swab is pulled upwardly.

It is a further object of the invention to provide a swab comprising a mandrel with a swab rubber or packing thereon formed of sections one of which is xed to the mandrel and the other of which is mounted on the mandrel so as to move into upper position in approximate vertical alignment with the xed rubber as the swab is lowered through the fluid in the well, or in case strong gas pressure is encountered in the well, said movable section being so mounted as to move into active position complementary to the fixed section so as to completely close tne space between the well pipe and the swab mandrel whereupon the liquid above the mandrel will be discharged from the well upon upward movement of the swab.

It is a further object of the invention to provide in a swab a sectional rubber whose sections are so shaped that their contacting faces will nt closely together when the swab is in active position to prevent leakage of the well liquid past the swab rubber.

With the above and other objects in view the invention has particular relation to certain novel features of construction, operation and arrangement of parts, an example of which is given in this speciiication and illustrated in the accompanying drawing, wherein:

Figure 1 shows a vertical sectional view of the swab in open position.

Figure 2 shows a side View oi two swabs in tandem relation in the well pipe.

Figure 3 shows a cross sectional view taken on the line 3 3 of Figure l.

Figure 4 shows a cross sectional View taken on the line 4-4 of Figure l, and

Figure 5 shows a cross sectional view taken on the line 5 5 of Figure 2.

Referring now more particularly to the drawing, wherein like numerals of reference designate the same parts in each of the figures, the numeral I designates the swab mandrel. As illustrated two of these mandrels are shown connected together in tandem relation with a swab rubber mounted on each of the mandrels. They are identical in construction and a specic description of one will suffice for both. Fastened on the lower end of the mandrel I there is a stop 2 secured in place in any preferred manner as by a set screw 3. Seatedv on the stop 2 there is a half round supporting cage 4 which embraces the lower end of the mandrel and which is formed of thin metal. Its upper and lower ends have the outwardly extending upper and lower flanges 5, 6 provided with under cut grooves and mounted on the outer side of this cage is the half round section 'I whose upper and lower ends are beveled and thereby reduced in diameter, said upper and lower ends fitting closely in the under cut portions or grooves of the anges 5, 6. The upper and lower pins 8, 9 are ttedthrough the corresponding flanges and through the ends 0f the section l and their inner ends are threaded and screwed into the mandrel as shown in Figure l and securely fasten the cage and swab section to the mandrel. The cage may have one or more openings as Iii through which the rubber may be moulded. The margins of the cage are cut on the diagonal as indicated at II, Figure l, There is a movable cage I2 similar in all respects to the cage fl and mounted on it is a swab rubber section i3 in all respects similar to the section l. The rubber I3 is pinned to its cage by the upper and lower set screws I5, IS which pass through the cage ilanges and the corresponding ends of the section. This swab section I3 is mounted to move longitudinally on the mandrel as well as to rotate in a spiral direction thereabout. Mounted on the mandrel l, in abutting relation with the upper end of the cage I2 there is a nut i6 which is welded to the adjacent end of the cage I2. The nut and the attached swab section are limited in their upward movement by means of the stop I l on the upper end of the mandrel. In case two swabs are connected in tandem, as shown in Figure 2, the connection may be made by an outwardly threaded pin I8 on one mandrel which may be screwed into an internally threaded box I9 on the adjacent end of the other mandrel.

The mandrel I is provided with external spiralled grooves 2li, 20 leading downwardly from the stop il and terminating slightly beneath the upper end of the rst swab rubber l. The nut I6, has the opposing inside ribs 2l, 2|, which iit loosely into said grooves so that as the movable swab rubber moves longitudinally along the mandrel it will also rotate about the axis of the mandrel. The pitch of the grooves is such that the movable swab section will rotate only a half turn from inactive to active position and from active to inactive position. The swab is preferably connected to the lower end of a wire line by means of which it may be lowered into and withdrawn from a well. While it is being lowered, the swab rubbers will be in coinciding relation as shown in Figure 2 until the` liquid is reached and as the swab is lowered through the liquid the section I3 will oat so that the mandrel will move downwardly relative thereto, said swab section I3 and the nut I6 moving upwardly relative to said mandrel until the nut I6 contacts the stop I'I. During such movement the movable swab section will also rotate a half turn about the mandrel into exact vertical alignment with the lower swab section as shown in Figure 1, thus allowing ample passageway for the liquid. It is advantageous for the vertical section to move into vertical alignment with the fixed section while lowering the swab for the reason that the overall transverse dimension of the swab is thereby reduced and the swab will more readily pass through a crooked pipe or a pipe that has been distorted. Upon upward movement of the swab the upper or movable swab section will immediately move downwardly relative to the mandrel and will at the same time rotate into position exactly opposite the xed section. The abutting faces of the swab rubbers and the abutting margins of the cages supporting said rubbers will fit closely together forming a complete plunger as the swab moves upwardly, at the same time tting closely within the well pipe 22, as clearly shown in Figures 2 and 5, so as to prevent the escape, of the well liquid above, upon upward movement of the swab and to secure its discharge from the well.

While moving the swab upwardly the pressure on the producing stratum is reduced sometimes causing a strong gas pressure in the well pipe beneath. In case of said excess pressure the movable section may be moved by it into open position thus allowing ample space for the escape of such pressure without danger of blowing the swab out of the well and injuring the workmen in the derrick.

What I claim is:

1. A swab comprising a mandrel, complementary swab sections, one of said sections being fixed on the mandrel and the other section being movable about the mandrel into inactive position in substantially longitudinal alignment with the xed section and into active position in registration with the fixed section, interconnecting means between the mandrel and the movable section for causing such movement of the movable section, upon longitudinal movement of the ,mandrel relative thereto.

2. A swab for wells comprising a mandrel, complementary swab sections on the mandrel, one of said sections being xed on the mandrel and the other section being longitudinally movable on the mandrel to positions into and out of registration with the fixed section, means for causing said movable section to rotate about the mandrel into longitudinal alignment with the fixed section, as it moves to one of said positions and into transverse alignment with the xed section when it moves to said other position.

3. A swab for wells comprising a mandrel, a plunger thereon, formed of sections relatively movable on the mandrel with respect to each other, into longitudinal alignment or into transverse alignment and means for causing relative rotative movement of the sections with respect to each other upon such movements into longitudinal or transverse alignment.

4. A swab for wells comprising a mandrel, complementary swab rubbers thereon shaped to close the space between the mandrel and the walls of the well, when in active position, one of said sections being movable into inactive position into longitudinal alignment with the other section, or into said active position and means for causing said movable section to rotate about the axis of the mandrel upon movement thereof to active or inactive positions.

5. A swab shaped to operate in a well and comprising a mandrel, complemental swab sections on the mandrel one section being relatively movable with respect to the mandrel into substantially longitudinally aligned position with respect to the other section or into substantially transversely aligned position with respect to said other section and connections between the mandrel and sections for causing such movement upon longitudinal movement of the mandrel.

6. A swab shaped to operate in a well and comprising a mandrel, complemental swab sections on the mandrel relatively movable with respect to each other into substantially longitudinally aligned position or into substantially transversely aligned position, said sections being shaped to close the space between the mandrel and the walls of the well when in said transversely aligned position and connections between the mandrel and sections to cause such movement upon longitudinal movement of the swab through liquid in a well.

7. A swab shaped to operate in a well and comprising a support, complemental swab sections on the support, one of said sections being fixed on the support and the other section being movable on the support, a nut on the support attached to the movable section, the movable section and nut being movable, as a unit, upwardly, relative to the iixed section, upon downward movement of the swab through the liquid in the well, to provide a passageway for the liquid, a stop arranged to limit said upward movement, said nut and movable section being movable downwardly, relative to the fixed section, upon upward movement of the swab, co-acting means between said movable unit and support effective to cause the movable section to move into substantially vertical alignment with the xed section upon such downward movement of the swab to provide said passageway, and to cause the movable section to move into substantially transverse alignment with the xed section, upon upward movement of the swab, to close the space between the support and walls of the well.

KLINE F. BUDD. 

